Tool-holder



M. W. SCHILLBERG.

TOOL HOLDER. APPLICATION FILED JULY 12} 1919.

1,342,600 Patented June s, 1920.

351. 5 a Imww a 1 ATTORNEY views.

UNITED STATES PATENT OFFICE.

MELKER WILLARD SCHILLBERG, 0F STRA'IFORD TOWNSHIP, FAIRFIELD COUNTY,

CONNECTICUT. I

TOOL-HOLDER.

To all whom it may concern:

Be it known that I, MELKER WILLARD SCHILLBERG, a citizen of Sweden, and a resident of the township of Stratford, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Tool I-Iolders, of which the following is a specification.

This invention relates to holders for the tools of lathes or the like and it appertains more especially to such devices as are adapted to hold the tools in a yielding manner.

The objects of the invention are 1. To increase the resiliency of the tool carrying part of a device of the nature set forth, and yet retain the full strength of its connection with the shank part of the holder.

2. To produce a device of the species mentioned requiring but few and simple steps in the manufacturing operations thereof and thereby reduce its cost.

3. To design a device of the kind referred to so as to avoid irregularly shaped or sharp-cornered transversal recesses, and consequently lessen its liability to crack during the hardening process.

4. To provide a device of the character described with an element for securely clamping the tool, which element shall be capable of being readily and correctly po-' sitioned in the seat provided therefor with a minimum expenditure of time and attention.

Other objects and advantages of the invention will become apparent as the specification proceeds.

With the aforesaid objects in View, the invention consists of the novel combinations and arrangements of parts hereinafter described in their preferred embodiments pointed out in the subjoinedvclaims, and illustrated on the annexed drawing, wherein like parts are designated by vthe same reference characters throughout the several In the said drawin Figure I is a top pl an view partly in horizontal section of the tool-holder illustrated in Fig. III, the section being taken on the irregular line I--I of the latter-named polnted figure, looking down in the direction out by the arrows; I

Fig.- II is a view similar to Fig. I show- Specification of Letters Patent. Patented J 1 119 8, 1920;

Application filed July 12, 1919. Serial No. 310,416.

ing a portion of the holder, the tool with its clamping element being omitted;

Fig. III is a front vlew of this'improved tool holder, a portion of the clamping ele-' ment being broken away to show interior construction Fig. IV is a vertical transverse section on the lines IVIV of Fig. III, viewed in the direction indicated by the arrows pertaining to the line last mentioned; and

Figs. V, VI, VII are respectively side, left and right hand end views of the clamping element used in conjunction with .this tool-holder.

Generally described, the invention comprises a shankadapted to be secured by one end in the tool-post of a lathe or other machine tool. From the other end of this shank extends a bowed member which is formed with a body separated therefrom by acurved gap having a terminal enlargement that is located on a line substantially median ofthe body. Londitudinally of this body is V largement. The larger one of these recesses intersects. the tools. seat and receives the head of an element adapted to have an over: hanging portion thereof bear on the tool. The shank of the element which is eccentric with respect to its head is passed through the smaller recess and is intended to have a clamping strain applied thereto in order to secure the tool in its assigned position in the holders body. j

The advantages of the invention as here outlined are best realized when all of its features and instrumentalities are combined in the one and same structure, but, useful devices may be produced embodying less than the whole.

It will be obvious to those skilled in the art to which the invention appertains, upon becoming conversant with the details thereof, that the same may be incorporated in several different constructions. The accompanying views, therefore, are submitted only as showing the preferred exemplification of the invention. :3 In these views the numeral 1 designates the shank of the tool-holder intended to be to the main or straight part thereof as indi- 7 secured in the toolpost of a rotative or reciprocatory metal working machine. Into the longitudinal sides of this shank are sunk recesses 2 which contribute to lighten the same and afford suitable places. for marking the makers name and the like. The fore-end of the said shank may be offset relatively terminal enlargement 14 which is locatedin a median vertical plane bisecting the body 9 cross-wise.

A hole 17 runs longitudinally through the middle portion of the said body and constitutes a seat for a cutting tool 18.

Although this tool has been shown to be of the thread cutting variety, it is understood that any other type of tool may be used tov equal advantage. In order to provide a clearance for the tail or rear end of the cutting. tool where the same passes through the fore-part 3 of the shank, anopening- 19v ofsimilar. shape as, but slightly largerthan the seat 17 is made therein. This opening terminates ,in a groove 20', where it runs out in=the side of the shank.

Extending transversely of the body 9, in-

termediate. the tool-seat 17 and the gaps 'terminalenlargement 14, are endwise intercommunicatingrecesses. 23' and 24 of different sizes. These recesses are axlally offset and arranged 1n such manner that their internal sides, preferably the uppermostv ones, are in alinement, while their opposite or lower sldes are 111. stepped-relatlon one to the other. The larger recess 23 1s bored sufiiciently deep to intersect a portion of.

the, hole 17 for a predetermined distance, as at 25, Fig. II, while the smaller recess Qt-is spaced from-the said hole 17 to leave a thin web 26 therebetween. Due to the peculiar arrangement, location and relative sizes of therecesses 14,23 and 24, they coact to increase the resiliency of the body 9" without weakening the bowed member 6. virtue of their cylindrical outlines,

which require only'plain machinework, it

is comparatively easy toform them in the body'9. Besides, by their use, all sharpcornered or irregularly shaped transversal depressions whichawould be likely to produce internal strains and cause the body to crack during the process of hardening the holder, are obviated.

The element for exerting a clamping action upon the cutting tool 18 in its seat 17,

consists of a bolt having a stem'29- and a head 30eccentric to the same. Both the stem and the head are of cylindrical formation, and the latter being the larger, extends over the former at one side thereof so as to produce an overhung ledge .31, but on the opposite side of the bolt, the head and stem are alinedj By reason of the fact that the design of the clamping element enables it to be turned from bar stock of the same diameter as the head thereof, there is less disturbance. of the grain or fibers in the bar from which it is out, than if the stem were necked down uniformly all the way around its head, and consequently a stronger clamp bolt is thereby produced.

hen the clamping element is to perform its binding function, the'stem 29 thereof,

is passed through the larger recess 23 into the smaller one 24. In view of the fact that the head 30 can become lodged .in the larger recess only one way, the operator cannot make a mistake in entering the same. In its operative position the overhung ledge 31 of the head bears upon the side of thecutting tool 18, near the upper edge thereof.

This edge of the tool, as can be seen most,

clearly in Fig. IV, protrudes beyond the bottom face of the recess 23 so that the head 30 cannot touch the latter. spects the head fills this recess and lies flush with the adjacent face ofthe body 9; It will also be noticed that the stem 29 of the clamping element cannot rub against the,

top face of the tool because of the intervening web 26. A nut 32v is made torengage the threaded outer end 33 of the stem 29 and when tightened up exerts pressure against the far or remote side of the body with its collared portion 34.

In other re- 1 Because ofthe angularly offset disposition I of the toolholders shank 1, with respect to its fore-part 3 and the-therewith'aline'd bowed member 6 and body 9, as well as on account of the flush arrangement of the clamp head 30 in the latter, it becomes pos,-.

sible to locate the cutting. point or edge of the tool: 18 close up to a piece of work held in the chuck of a lathe. Furthermore, due

to the structural conformation ofIthe open, 7

edged recess 20 in the fore-part. 3 of the holders shank, it is an easy matter, after thenut hasbeen loosened, to pull out the cutting tool 18 rearwardly, for sharpening] or inspection, without disturbing the setting of the tool-holder in the tool-post, or having to move back-the cross-slide of the lathe,

as usually isthe case. p

7 While acertain preferred embodiment: of this device has been shown and described,

itwill be understood that changes in the form, arrangements, proportions, sizes and details thereof may be made, without de-.

parting from the scope of the invention as defined by the appended claims.

Having described my invention what I desire to secure by Letters Patent and claim, is

l. A tool holder comprising a shank, a tool carrying body, and a member connecting the latter with said shank but separated therefrom by a gap terminating in a vertical plane substantially median of the body, said body having a seat for the cutting tool extending longitudinally therethrough and being provided transversely with axially offset recesses located approximately in the said plane, one of said recesses forming an intersection with said seat, combined with an eccentrically headed element adapted to be received in said recesses and capable of exerting a clamping action upon that part of the tool which passes said intersection.

2. A tool holder comprising a shank, a tool carrying body, and a bowed member yieldably connecting the latter with said shank, said member being spaced from said body by a curved narrow gap the inner end whereof terminates in a cylindrical enlargement located substantially on a median line passing vertically through the body, the said body being provided longitudinally with a seat for the cutting tool and having transversely thereof endwise communicating recesses of cylindrical formation disposed approximately on said median line, said recesses being of different sizes and axially offset one with relation to the other, the larger one of said recesses intersecting said tool seat, combined with an eccentrically headed element bearing upon the tool through said intersecting recess so as to clamp it in its seat.

3. A tool holder comprising a shank, a member extending from said shank upwardly, outwardly and thence downwardly, and'a tool-carrying body connected to said member but separated therefrom by a curved gap, said gap terminating in an enlargement .at the juncture of the member with the body,

said body having longitudinally therethrough a seat for the cutting tool and being provided intermediately of the latter and the gaps enlargement with intercommunicating axially offset recesses of different sizes, the larger of said recesses forming an intersection with the tools seat while the smaller one is spaced from the same, combined with a clamping element including a stem with an eccentric head, said stem being adapted to enter the smaller recess and have its said head lodged in the larger recess flush with the adjacent face of the body in position to exert a binding action upon the tool through said intersection.

MELKER WILLARD SCHILLBERG. 

